Chapter 1: The Book of the Sunnah
It was narrated that Ka' b bin 'Ujrah said: "The Messenger of Allah mentioned a Fitnah (tribulation) that had drawn nigh. Then a man passed by with his head covered. The Messenger of Allah said: 'On that day, this man will be following right guidance.' I leapt up and took hold of 'Uthman' s arms, then I turned to face the Messenger of Allah and said: 'This man?' He said: 'This man.'"
Sunan Ibn Majah 111